The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of making a decision about when it's the best time to plant tall phlox is to examine the USDA zone info for Denison.

Planting Calendar for Tall Phlox

Frost tolerance for tall phlox:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant tall phlox a little bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant tall phlox in Denison is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant tall phlox and expect a good harvest is probably September. If you wait any later than that and your tall phlox may not have a chance to fully mature. Starting your tall phlox indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Denison the average date of last frost happens on March 15. You should expect an average low temperature of 10°F in the coldest months of winter.

Always keep in mind that USDA zone info for Denison is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Denison there is a last frost after March 15 so just be sure to be ready to cover your tall phlox if you have a surprise late frost.

USDA Zone Info for Denison

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Denison

You may be interested in your other planting guides for Denison.